Fastening device for pulp-screens.



M. E. HODGDON.

FASTENING DEVIGE FOB. PULP SCREENS.

APPLICATION FILED FEB. 13, 1913.

1,085,048. Patented Jan. 20, 1914.

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UNITED STATES PATEN @FFIQE.

MELVIN E. HODGDON, 0F FI'IGHIBURG, MASSACHUSETTS.

FASTENING DEVICE FOR PULP-SCREENS.

To all whom it may concern:

Be it known that I, MELvIN E. HoDoDoN, a citizen of the United States, residing at Fitchburg, in the county of lVorcester and State of Massachusetts, have invented certain new and useful Improvements in Fastening Devices for Pulp-Screens, of which the following is a specification.

The object of the present invention is to provide a simple fastening device for screens used in the vats of paper and pulp mills. Usually the screens are held down by screws, either directly or through intermediary clamping strips running the whole length of the screen, but as this requires the loosening and tightening of hundreds of screws every time the screens are to be changed, considerable time will be wasted, not to mention that the threads in the screw-holes soon wear out. In the present invention, on the other hand, a lever on either side of the screen has simply to be thrown over in one direction, after its clamping has been loosened, and the whole screen is free to be taken out.

One embodiment of this invention is illustrated in the accompanying drawings, where- Figure 1 shows a side view partly in section of a vat with my improved screen fastening device; Fig. 2 is part of a section along line 22 of Fig. 1; Fig. 3 is a transverse section in larger scale of the locking device; and Fig. A a plan view of Fig. 3 with the screens removed.

The vat A of the usual construction, is provided with cross bars B for supporting the screens C, and on top of these bars are situated housings D for a pair of tightening rods E, which are preferably made from non-corrosive material. These rods extend the whole width of the vat and project on one side thereof ending with a horn F which is bent upward. The bars are of cylindrical cross section and have longitudinal undercut grooves out along the upper side thereof providing an engaging tongue on each rod and forming a dove tail groove with a flat bottom in each pair of rods. Corresponding oppositely presented undercut grooves together forming dove tails are formed in the lower side of the screens C constituting gripping faces for the grooves in the rods. The longer sides of the screen are made to abut against each other along the intermediate line, between the two rods,

Specification of Letters Patent.

Application filed February 13, 1913.

Patented Jan. 20,1914. Serial No. 748,261.

forming a tight joint when drawn together and locked down by these rods.

At the end of the vat where the tightening rods E project through, a bracket G for each pair of rods is situated and secured by screws on the side of the vat. At the upper end of this bracket a pair of arms are provided intended to receive clamping bolts H which engage the guide-ways G in the shoe piece J which at its lower end has a socket intended to receive the horn F of a tightening rod. At the upper end of the shoe piece J is provided another socket J for the actuating lever K. This lever is common for all the shoes and slips easily into the socket of any of them. At the two extreme ends of the vat A, a single tightening rod E with corresponding housing D guide are G and shoe piece J are provided.

When the screens D have been all placed in the vat and secured by their respective tightening rods E, E sealing pieces L with rubber strips L on their under sides are placed inside the vat around all four sides. These are pressed down against the screens C and held in place by means of pressure feet M which are actuated by compressing screws N turned by a wrench 0. These pressure feet and screws are all housed in pockets in the sides of the vat, so that only a toe M projects inward into the vat, and engages with the top of the sealing pieces L.

The operation of the device is as follows: Supposing the screens are to be removed from the vat, the first operation is to release the sealing pieces L by raising the feet M, using the wrench O to turn the screws l. As soon as the sealing pieces L have been taken away, the lever K is inserted in the shoe pieces J, one after the other, and the shoes together with the tightening rods E are turned outward after loosening the clamping bolts H. As the rods E have now released their hold on the screens, the latter can be removed.

I claim:

1. In combination with a screen member having an undercut groove, a fastening device comprising a tightening rod, having a cylindrical surface, mounted to oscillate about its axis, and constructed with an undercut groove along its cylindrical surface providing a tongue adapted to enter the undercut groove of the screen, and thereby hold down the screen in place when said rod is turned in one direction.

2. In a fastening device for screens, a tightening rod and a housing therefor in which the rod is mounted to oscillate, interengaging members on the screen and on the rod, said inter-engaging members comprising a dovetail on the under side of the screen and a co "responding groove along the opposite side of said rod, whereby the screen will be held down in place when said rod is turned in one direction. 7

3. In combination with a screen member having an undercut groove, a fastening device comprising a tightening rod, having a cylindrical surface, mounted to oscillate about its vaxis, and constructed with an un dercut groove along its cylindrical surface providing a flat face bearing against the under surface of the screen member, and a tongue adapted to enter the undercut groove of the screen, and thereby hold down the screen in place when said rod is turned in one direction.

4. In combination with a pair of screen members having undercut grooves, a fastening device comprising a pair of parallel tightening rods, having cylindrical surfaces about their axes, and constructed with oppositely presented undercut grooves along their cylindrical surfaces, providing oppositely presented overhanging tongues; said rods being located to interlock with and draw together and downwardly, the pair of screen members, when the rods are turned in opposite directions.

In a fastening device for screens, a tightening rod and a housing therefor in which the rod is mounted to oscillate, interengaging members on the screen and on the rod, whereby the screen will be held down in place when said rod is turned in one direction, and means for turning said rod, said means comprising a shoe piece engaging one end of said rod and a detachable lever for said shoe piece.

6. In a fastening device for screens, a tightening rod and a housing therefor in which the rod is mounted to oscillate, interengaging members on the screen and on the rod, whereby the screen will be held down in place when said rod is turned in one direction, and means for clamping said rod in its locked position; said means comprising a bracket having guide ways, a shoe piece engaging one end of said rod and a clamping member on said shoe piece, engaging said guide way and adapted to secure said shoe and said bracket.

7. In a pulp screen, the combination of a screen member having an undercut groove on its underside, a tightening rod having an overhanging tongue adapted to engage in said groove, means for rotating the rod to interlock the tongue and groove, and a trough-shaped housing having its open side closed by the screen member and inclosing said tightening rod.

The foregoing specification signed at- Fitchburg, Massachusetts this sixth day of February, 1913.

JOSEPH SMILEY, BoYnnN B. LUNr.

(topics of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

